The invention relates to a discharge apparatus for media. Such discharge apparatuses are more particularly used for spraying a fluid. Preferably the fluid contains one or more pharmaceutical substances.
Such discharge apparatuses are e.g. known from DE 198 07 921 and have a casing on which is arranged in relatively movable manner an actuator. The actuator can be moved with respect to the casing by a path corresponding to an actuating stroke path. A control unit is provided, which at least determines the time since the last actuation of the actuator. There is also an actuating stop actuatable in controlled manner by the control unit, the actuating stop in its blocking position blocking the performance of an actuating stroke and in its release position allowing the performance of an actuating stroke.
Such discharge apparatuses are used if, to avoid an excessively high active substance concentration, the delivery of the medium to be discharged is to take place in time-extended manner. This is e.g. the case if the medium to be discharged contains a pharmaceutical substance or substance combination to be administered by the patient. As a result of the possibility of being able to block an actuation of the actuator for a certain time after the performance of an actuating stroke, a rapidly succeeding administration of the active substance is prevented.
The problem of the invention is to provide an easily manipulatable and long term-usable discharge apparatus.
Based on the preamble features, the problem of the invention is solved by the characterizing features of the independent claims.
An inventive discharge apparatus for media, particularly for spraying a fluid preferably containing a pharmaceutical substance has a casing. On the casing is located an actuator, which can be moved relative to the casing by a path corresponding to the actuating stroke path. The discharge apparatus has a control unit, which at least determines the time which has elapsed since the last actuation of the actuator. An actuating stop, operable in controlled manner by the control unit, in its blocking position prevents the performance of an actuating stroke and allows such an actuating stroke in its release position. Such an actuating stop has a blocking member, which can be brought by means of an electromagnet from the release position into the blocking position and/or from the blocking position into the release position.
As a result of this measure it is advantageously ensured that for switching the actuating stop from the blocking position into the release position and vice versa only a relatively small amount of energy is required, namely the quantity in order to energize briefly an electromagnet, preferably corresponding to a relay and to briefly build up an adequately strong electromagnet field. The blocking action of the actuating stop is achieved in that the blocking member acts in the mechanism of the actuator in such a way that a blocking action occurs. The blocking member is correspondingly supported and the force bringing about the block or stop does not have to be applied by the electromagnet or by the power supply of the actuating stop.
A preferred construction of the discharge apparatus is obtained if actuation is stopped if, since the preceding actuation, a preset time interval has not yet elapsed.
Preference is also given to a discharge apparatus having a contact switch bound into the circuit supplying the electromagnet and which interrupts the electromagnet power supply for as long as the actuator is not moved by a minimum path out of its unactuated rest position. Preferably the amount of the minimum path is smaller than the idle path of the actuator at the start of an actuating stroke.
According to a first, preferred development of the invention the blocking member is constructed as a bistable element and consequently is located without any constant action of a force either in the release position or in the blocking position. According to alternative developments of the invention it is possible to have a monostable blocking member construction. Consequently the blocking member either remains in the blocking position or in the release position and is kept in the release or blocking position for the duration of the electromagnet action.
According to a preferred development of the features of the preamble of claim 1 a switch is located on the discharge apparatus, which can be manually operated and whose operation makes it possible to perform a preset, small number of actuating strokes without the actuating stop having to be brought into the blocking position. Following the operation of the switch it is possible to perform a small number of actuating strokes, particularly between two and ten strokes, without any action of the actuating stop. In the case of discharge apparatuses according to the invention, e.g. in pump atomizers, it is possible to ensure as a result of this measure that in the first actuating stroke administered to the patient the preset discharge quantity is delivered. Particularly with pump atomizers, but also with other discharge apparatuses, as a result of the design it is initially necessary to prime the discharge apparatus or suction pump following prolonged storage or from the packing time, e.g. due to the need for a sterile or at least approximately sterile packing. For this several pump strokes must be performed and during said pump strokes only partial medium discharge takes place and subsequently air is also discharged as the number of actuating strokes decreases. Preferably, independently of the volume of the pump atomizer or other technical circumstances, during the first or first few discharge strokes it is necessary, prior to the first application of the discharge element to perform said xe2x80x9cemptyxe2x80x9d actuations, so that during the first actuation for administering the active substance, it is ensured that the desired, prescribed medium quantity is discharged. In the case of pump atomizers the number of necessary strokes is dependent on the volume of the pump atomizer, i.e. the size of the volume of a discharge or actuating stroke. It is also dependent on the medium to be discharged. In case of doubt the necessary number of empty actuating strokes is to be empirically determined at the start of use of the discharge apparatus and correspondingly preset.
According to a preferred development of this apparatus a second time interval is preset during which the preset number of actuating strokes must be performed. If the second time interval is exceeded, it is in particular possible to bring the actuating stop into its blocking position. This ensures that a time link between the actuation of the switch and the performance of the number of actuating strokes is maintained. This can in particular prevent incorrect operations and actuations by the user. It must simultaneously be avoided that through repeated operation of the switch does not allow overdosing of the active substance.
According to another development of a discharge apparatus according to the invention, the control unit has an externally accessible interface by means of which it is possible to act on the control unit. The interface is accessible from the outside. By means of the interface it is possible to set at least one of the following parameters for the control of the actuating stop by the control unit: duration of the first time interval, duration of the second time interval and number of actuating strokes performable after operating the switch.
This construction of the invention has the advantage that the simple adaptation to different time intervals and different numbers of empty actuating strokes can be variably preset at the start of the use of a discharge apparatus. As a function of the filling and dimensioning of the discharge apparatus, e.g. in the pharmacists when delivering a medicament the necessary setting can take place, preferably in patient-individual manner. This permits a high flexibility of the discharge apparatuses and a better adaptation to different patients and active substances.
According to another advantageous development of the invention it is possible to ensure that the possible successive number of actuations which can take place after operating the switch can only be carried out if a communications means is contacted at the interface in simultaneous manner. The communications means can either be a computer or a passive part. This advantageously ensures that the performance of the number of actuations without the intervention of the actuating stop can only be performed by trained personnel, e.g. the pharmacist when delivering the medicament. This further increases safety for the user. Thus, it is no longer possible to get round the actuating stop by operating the switch several times.
According to an advantageous further development of the invention the presettable number of actuating strokes successively performable without the intervention of the actuating stop can be effected during the initial actuation of the actuator. This permits the putting into operation of the discharge apparatus in simple manner without further measures and without the user necessarily being given the possibility of performing several successive actuating strokes at a later time without this being prevented by the action of the actuating stop.
According to an advantageous development of the invention a single actuation of the actuator and consequently the performance of an actuating stroke is also possible after a failure of the power supply. This possibility exists following an irreversible removal of a securing element.